1. Field of Invention
The invention relates to a zipper switch for the DC motor of a ceiling fan and, in particular, to a zipper switch that switches on a circuit and provides an instantaneous electrical current.
2. Related Art
For an AC ceiling fan, a common trigger method is implemented by continuously providing electricity to start the fan or change the rotation speed thereof. As shown in FIGS. 4 to 6, a zipper switch 9 that can continuously provide electricity in the prior art consists mainly of an upper shell 91 and a lower shell 92 connected together. The upper shell 91 has an activating disk 911, a zipper 912, a torque spring 913, and a pressing cover 914. The activating disk 911 and the torque spring 913 are pivotally disposed at the center of the upper shell. The zipper 912 is connected to the activating disk 911. The center on one side of the activating disk 911 is protruded with four pushing parts 9111 with a slant surface. By pulling the zipper 912, one rotates the activating disk 911 with respect to the center of the upper shell 91. The pushing parts 9111 are driven to rotate along the same direction and advance by the distance of one pushing part. On the other hand, when the zipper 912 is released, the torque spring 913 makes the pushing parts 9111 rotate in the opposite direction and back by the distance of one pushing part.
The above-mentioned lower shell 92 has a rotating block 921 and two conductive elastic plates 922. The rotating block 921 is pivotally disposed at the center of the lower shell 921. It has a conductive elastic plate 9211 to form contact points on both sides. The outer side of the rotating block 921 is disposed using four passive parts 9212 corresponding to the pushing parts 9111. The conductive elastic plate 922 is disposed in the vicinity of the rotating block 921. Therefore, the pushing force produced when the pushing parts 9111 rotate forward can push the passive parts 9212, so that the passive parts 9212 rotate one quarter of the circumference along one direction. After first puling and releasing the zipper 912, it is switched a connect mode, as shown in FIG. 5. When the zipper 912 is pulled and released again, it is switched to a disconnect mode, as shown in FIG. 6. This enables the two contact points of the conductive elastic plate 9211 to switch between connect and disconnect modes with the conductive elastic plate 922, producing the On and Off effects.
However, the zipper switch can only be applied to an AC motor. For a DC motor, the trigger method has to be achieved using an instantaneous current. The conventional zipper switch cannot accomplish this goal.